The invention relates to a flow rate meter as described herein. A flow rate meter is already known but in which the characteristic curve of the flow rate meter can be affected only to a limited extent, or at relatively great expense, by the selection of the contour of the flow channel. Particularly when the flow rate meter is used in a motor vehicle at full load, there is a relatively large amount of error in positioning of the flow rate meter, which translated into a large error in flow rate measurement.